The purpose of the Morphology Core has been and will continue to be to perform tissue processing sectioning, and histochemical and immunohistochemistry staining for Program investigators and their associates. In addition, the Core provides technical assistance and training in in situ hybridization and morphometry. Because each project in this renewal proposes numerous experiments requiring histological processing of samples and microscopic detection techniques, the Morphology Core will continue to be an integral and essential component of this Program Project Grant. The Morphology Core is staffed by experienced research technicians and will occupy dedicated and fully equipped laboratory space. Furthermore, the Morphology Core will, as it has done for the past four funding cycles, provide a center for correlative interactions among the Program investigators in their independent, yet complementary studies on lung biology.